Carboxylic acids of capillary action



names 2c, 1938 UNITED-STATES PATENT OFFICE GARBOXYLIC ACIDS OF CAPILLABYACTION CONTAINING ISOCYCLIC RING-SYSTEMS AND A PROCESS OF PREPARING KurtSchimmelschmidt, Frankfort-on-the-Main- Hochst, Germany, assignor to I.G. Farbenindustrie Aktiengesellschaft, Frankfort-on-the- Main Germany NoDrawing.

rial No. 52,929. 1934 Application December 4, 1935, Se-

In Germany December 7,

4 Claims. (Cl. 260-514)- The present invention relates to carboxylicacids, of capillary action, containing isocyclic ring-systems and to aprocess of preparing them.

I have found that compounds of the general formula 'R1A--Ra-COOH whereinR1 means an alhl or cyclo-alkyl radical,

R: an allwlene radical and A an'aromatic or hydroaromatic ring-system,

are obtainable by introducing fatty acid radicals into 'alkylated orcycloalkylated aromatic hydrocarbons by condensing alkylated orcycloalkylated aromatic hydrocarbons with aliphatic dicarboxylic acids.including their anhydrides, acid chicrides or ester-acid chlorides and.reducing the ketocarboxylic acids thus formed to the correspondingcarboxylic acids. In order to .obtain the hydroaromatic compoundscorresponding to the above formula, these alkylorcycloalkylaryl-substituted fatty acids or the esters thereof aresubjected to a catalytic hydrogenation and, if necessary, thehydrogenated esters are saponified.

The alkyl-a'ryi-fatty acids of the formula R1- A-Rs-COOH wherein R1means alkyl, I A means an, aromatic rial-system and It: meansCHsQI-IsCHs, or W,

are, for instance, obtained by condensation of the alkylated aromatichydrocarbons-withlactones or functional derivatives of the succinic,acid, the glutaric acid or the adiplc acid series, such as theiranhydrides, chloridesrand esterracid chlorides. The keto-carboxylicacids obtained by tainable according to these methods may, behyusing theacid ,anhydride's, the acid chlorides or the, ester-acid chlorides, arereduced to the corresponding fatty acids in an alkaline solution in thepresence of line dust or catalytically' "activated hydrogen. 1

The alkylor cycloalkyl aryl'f'atty acids obdrogenated, if necessary,with formation of hydroaromatic compounds which are completely saturatedwith hydrogen. The hydrogenation is carried out in. a particularlysmooth manner by treating with hydrogen the esters of these acids withmonohydric or polyhydric alcohols in the liquid phase 'at a temperaturebetween 130 C.

' and 200 C. in the presence of a nickel catalyst and with applicationof pressure. The esters of the hydrogenated alkylaryi-fatty acids thusobacid, alkyl-phenanthrene fatty acids, 4-isobutyl-.cyclohexyl-gamma-butyric acid, i-cyclohexylcyclohexyl-gamma-butyricacid, dicyclohexylmethane-4-gamma-butyric acid etc. I

As alkylated aromatic hydrocarbons there may be mentioned besidestoluene, ethyl-, propyl-, butyl-benzenes, methylnaphthalene,cyclohexylbenzene or the like, the products which are, for

'instance, obtained by reaction of benzene, naphthalene or phenanthrenewith commercial mixtures of alcohols, as, for instance, isobutyl oil (aby-product which is obtained in the methanolsynthesis) vor with themixtures of alcohols obtained from commercial fatty acids byhydrogenation, or with mixtures of the alcohols obtainable by'theoxidation of paraflln; furthermore, the condensation products frombenzene,

' naphthalene or phenanthrene with olefines or the polymerizationproducts thereof as, for instance,

di-isobutylene, or with the unsaturated constitucuts of the compoundsobtained in the cracking process or with oil of turpentine.

Whereas the alkali salts of aryl-fatty acids as for instance,phenylacetic acid, phenyl-gammabutyric acid and so on, do not froth inaqueous solution, the alkali salts of alkylaryl-fatty acids and thehydrogenation products thereof show a very good foaming power. Theirwetting action surpasses that of the alkali salts of the corre--sponding natural fatty acids, The alkali salts of the perhydrogenatedalkylaryl-fatty acids show in spite of the completely saturatedcharacter of the carboxylic acids from which they are prepared, anexcellent solubility in water. 'It is easily possible to prepare a coldparent solution of 20% strength and even of a higher percentage thisbeing impossible when the saturated aliphatic carboxylic acidscorresponding to them in the length of the chain are used. Furthermore,they show avery good washing action by which they surpass, for instance,on removal of the fat from wool, the alkali salts of saturated naturalfatty acids, for instance, lauric acid. The perhydrogenatedalkylaryl-fatty acids are, on account of their saturated character,entirely stable. They are suitable, so far as they are liquid at roomtemperature, on account of their good lubricating power, as glidingagents for difierent purposes, for instance, greasing of wool, and showcertain advantages over the oleic acid hitherto used for this purpose.

The following examples serve to illustrate the invention, but they arenot intended to limit it thereto; the parts are by weight:

(1) 134 parts,of'n-butylbenzene (l-phenylbutane) are mixed with 100parts of succinic acid anhydride and 500 parts of tetra-chlorethane andat 20 C.-30 C. 270 parts of anhydrous aluminium chloride are slowlyintroduced. After about 12 hours the mixture is heated to 50 C. untilthe reaction is finished; then it is poured on ice and after theaddition of hydrochloric acid the whole is subjected to a steamdistillation. The condensation product remains in the distillationvessel, after the complete elimination of the tetrachlorethane, in theform of a solid, granular mass and is separated from the aqueoussolution of aluminium salts by filtration with suction. The crudeproduct may be purified by recrystallization from chloro-benzene andthere is'thus obtained the 4-butylphenyl-gamma-oxo gamma butyric acid ofthe following formula:

in the form of pearly leaflets melting at 115 C. to 116 C. I

200 parts of 4-butylphenyl-gamma-oxo-gamma-butyric acid are introducedinto a suitable hydrogenation autoclave together with 200 parts of waterand the calculated quantity of caustic soda solution and the mixture istreated with hydrogen, after the addition of a nickel catalyst, at atemperature between 70 C, to 200 C. under apressure of20 to 100atmospheres. When the absorption of hydrogen is'finished the content ofthe autoclave is freed from the catalyst by filtration with suction andthe reaction product is isolated from the alkaline solution byacidification. The 4-butyl-phenyl-gamma-butyric acid of the followingformula:

cm-(onnOmmp-coon is-thus obtained, boiling at 170" 0.111 a vacuumorganic solvents.

of 3 mm. and solidifying zit-53 C. in the form of a white solid masswhich on crushing falls into fatty flaky leaflets. It is insoluble inwater and very easily soluble in niost of the organic. solvents. Indilute caustic alkali solutions it is very easily soluble and yieldsstrongly foaming solutions. The solution of 20% strength of the sodiumsalt thereof in water is a completely clear, liquid even when cold. Theaqueous solution of the sodium salt may be used as a wetting agent.

(2) The 4-butyl-phenyl-gamma-butyric acid obtainable according toExample 1 is. esterified with methanol and sulfuric acid. The 4-buw1-phenyl-gamma-butyric acid-methylester is obtained as a colorless liquidboiling at 124 C. in

.a vacuum of 3 mm. and at 162C. in a vacuum of 12 mm. The esterisintroduced into a hydrogenation autoclave together with a nickelcatalyst and treated at 130 C. to 200 with hydrogen under a pressure of50 to 150 atmospheres until the absorbtion of hydrogen is finished. The

contents of the autoclave are filtered from the catalyst and subjectedto distillation. The 4- butyl-cyclohexyl-gamma-butyric acid-methylesteris obtained in the form of a colorless liquid boiling at 125 C. in avacuum of 3 mm. By saponifying the ester the4-hutyl-cyclohexylgamma-butyric acid of the following formula:

CBi-CHE is obtained, constituting atroom temperature a colorlesssemi-solid mass and boiling at 150 C.

in a vacuum of 3 mm.- It is practically insoluble in water, but veryeasily soluble in most of the It is easily soluble in dilute causticalkali solutions and forms even in a solution' of 20% strength of thesodium salt thereof in water a clear liquid in the cold. The aqueoussolutions of the sodium salt are suitable as wetting agents, emulsifyingagents and washing agents.

(3) By replacing in mample 1 the butylbenzene by 160 parts ofcyclohexylbenzenathere is obtained by way of the4-cyclohexy1-phenyl-gamma-oxo-gamma butyric acid melting at 132 6. to133 C., the 4-cyclohexyl-phenyl-gamma-butyric acid of the followingformula Una-O \CHFCHS in the form of a colorless fatty mass having thestructure of leaflets and solidifying at 56 C. The dilute aqueoussolutions of its sodium salt have a very good foaming action and aresuitable as wetting agents. From concentrated aqueous solutions thesodium salt crystallizes in the form of pearly leaflets.

(4) By replacing in Example 2 the 4-bu'ty1- phenyl-gamma-butyric acid bythe 4-cyclohexylphenyl-gamma-butyric acid obtainable according toExample 3, there is obtained by way of the4-cyclohexyl-phenyl-gamma-butyric acid-methyl ester and the4-cyclohexyl-cyclohexyl-gamma-butyric acid-methyl ester, bothrepresenting colorless liquids boiling under a pressure of 3 mm.

' at 140 to 145 C.,- the 4-cyclohexyl-cyclohexylgamma-butyric acid ofthe following formula 170 C. alkali solutions to strongly foamingliquids.

CHrCHr R: a-O-c o-cm-cm-coon p-Ocm-onrcm-oo on an n-cm-cm-cm-co on Hr H:

CHrCHz-CHr Melting at i1s-1ao O Methyl ester boiling under a pres-Boiling under a pressure of 3 mm. at 150 sure of 3 mm. at 134 C. 0.liquid.

CH: Bolling under apressure cl3 mm.at

CH- Melting at 93 C Y Methyl ester boiling under a pres- Boiling under apressure of 3 mm. at 150 CHr-CH: sure of 3 mm. at 133 C. 0. liquid. CH:Melting at 44 C. to 45 0., boiling solidifying at 66 C., iling under aunder a pressure cl 2 mm. at 153 pressure 012mm. at 160 C. E-CHrCHrMelting at 07 C. to 90 C C.

CHI CH;-(CH;);- Melting at 95 C Melting at 56 0. to 57 C Btailing undera pressure oi 2 mm. at 170 CHI-(C Hi):- Melting at ION-104 C Solidilylngat 62 0., boiling under Boiling under a pressure of 2 mm. at 180 7apressureoi3mm.at20b C. C. I

CHr-(GHs)n- Melting at 9l-02 O Boiidiiying at 71 C.

forming a white crystallne mass solidifying at hydrogenated benzeneradical being colorless, liq- 83 C. and boiling under a pressure of 3mm. at

uid to solid bodies dissolving in dilute caustic to formdiphenyl-4-gammaeoxo-gamma-butyric add, melting at 187 C. to 188 C. andtransforming it by way of diphenyl-i-gamma-butyric acid' melting at C.to 121 C. into the 4- cyclohexyl-cyclohexyl-gamma-butyric acid.

(5) In analogous manner there may be obtained the products indicatedinthe following Rmcmncoon wherein R1 means a member of the groupconsisting, of alkyl and cycloalkyl radicals containing at least 3carbon atoms and A means a hexa- 2. The 4-butyl-cyclohexyl-gamma-butyricacid of the formula CHr-CH,

CH-(CH:)r-COOH CHI-O 1 I being a colorless semi-solid mass boiling at150 C. under a pressure of 3 mm. and being easily soluble in dilutecaustic alkali solutions.

3. The 4-cyclohexyl-cyclohexyl-gamma-butyric acid of the formula CHz-CHI'CHr- CH1 cg, cn -c CH-(CH1)s-CO on CHg-C CHr-C g 'ing of alkyl andcycloalkyl radicals containing at least 3 carbon atoms, with succinicacid anhydride, reducing the keto-carboxylic acids thus obtained to thecorresponding substituted butyric acids, treating the acids thusobtained, in the .form of their esters, in the liquid phase withhydrogen under pressure at a temperature between C. and 200 C. in thepresence of a nickel catalyst and finally saponifying the reactionproduct.

KURT SCHIllfldEUSCI-IMD'I.

